Heretofore, an electronic clock whose minute hand is moved not at one step per minute but at one step at 15-second intervals, at 20-second intervals or the like has been commercialized. For example, in case of a 20-second-interval movement, such an electronic clock performs three step movements per minute so as to thereby gain one minute. A reason for such an arrangement is to know an approximate second even by the minute hand alone and to reduce a rotating angle of the minute hand so as to thereby facilitate a drive control of a step motor or the like.
On the other hand, if a correction of time, a setting of alarm time or the like is performed in the driving system as described above, this is very troublesome. More specifically, when it is desired to move the minute hand by one or two minutes alone, this driving system has a shortcoming in which a switch operation must be often carried out. Therefore, the applicant discloses, in Japanese Patent Application Laid-open No. 57-169690/1982, a system in which one switch operation allows the clock to gain one minute at the time of setting the alarm.
However, in the conventional electronic clock, the step of the minute hand is normally set to, for example, the 20-second-interval movement. Therefore, when a source voltage is reduced and thus the electronic clock is stopped, the minute hand may be stopped between one minute scale and another minute scale. When a battery replacement or the like is performed and then the minute hand is corrected, this causes the clock to gain one minute each. Thus, the minute hand cannot be set to the minute scale, whereby the time correction is very difficult to perform.